1. Technical Field
The present invention relates to a liquid ejecting apparatus such as an ink jet recording apparatus and a method of controlling the liquid ejecting apparatus, and more particularly, to a liquid ejecting apparatus which drives a pressure generation unit by applying a driving waveform of a driving signal to the pressure generation unit and ejects a liquid from nozzles by causing a change in a pressure of the liquid in a pressure chamber communicating with the nozzle and a method of controlling the liquid ejecting apparatus.
2. Related Art
A liquid ejecting apparatus is an apparatus that includes an ejection head and jets (ejects) various kinds of liquids from the ejection head. As the liquid ejecting apparatus, an image recording apparatus such as an ink jet printer or an ink jet plotter can be exemplified. In recent years, the liquid ejecting apparatus has been applied to various kinds of manufacturing apparatuses, since the liquid ejecting apparatus has characteristics in which a very small amount of liquid can be accurately landed on a predetermined position. The liquid ejecting apparatus is applied to, for example, a display manufacturing apparatus that manufactures a color filter such as a liquid crystal display, an electrode forming apparatus that forms an electrode of an organic EL (Electro-Luminescence) display, an FED (Field Emission Display), or the like, a chip manufacturing apparatus that manufactures a biochip (biochemical element). A recording head of an image recording apparatus ejects liquid-phase ink and a color material ejecting head of a display manufacturing apparatus ejects solutions of color materials of R (Red), G (Green), and B (Blue). Further, an electrode material ejecting head of an electrode forming apparatus ejects a liquid-phase electrode material and a bio-organic substance ejecting head of a chip manufacturing apparatus ejects a solution of a bio-organic substance.
A liquid ejecting head is configured such that the pressure of a functional liquid in a pressure chamber is changed by applying a driving waveform to a pressure generation unit such as a piezoelectric vibrator and driving the pressure generation unit, and the change in the pressure causes a liquid to be ejected from nozzles. In a liquid ejecting head using such a liquid ejection method, it is known that the characteristics such as an amount of displacement are changed with an increase in the number of times of driving. For example, when a piezoelectric vibrator which is a kind of pressure generation unit is repeatedly driven, polarization characteristics are changed and the amount of displacement thus tends to deteriorate. The change in the polarization characteristics is caused since the repetition of the driving causes a piezoelectric body to be polarized in a direction different from the direction of an applied electric field. When the characteristics change (deteriorate), a problem may arise in that an amount of ink to be ejected from nozzles or flying speed (ejection characteristic) deteriorates when the driving waveform of the initial setting is used and the pressure generation unit is driven. Further, since the degree of change in a variation in the characteristics occurs depending on the use status of the nozzles, for example, there is a concern that unevenness or streaks may occur in a recorded image or the like.
To resolve this problem, a configuration in which the ejection characteristics are prevented from deteriorating by correcting a driving voltage depending on a driving status of a pressure generation unit of each nozzle line has been suggested (for example, see JP-A-2009-066948).
In this configuration, however, the driving voltage increases as the characteristics gradually deteriorates. Therefore, since the pressure generation unit corresponding to the relatively frequently used nozzles further deteriorates, there is a concern that the variation in the characteristics further worsens.